Don't close mind to coal

THE EDITOR, Sir:The dangers of coal have decreased with advancements in clean coal technologies. These technologies minimise the release of pollutants, such as oxides of sulphur (SOx) and nitrogen (NOx), and particulate and trace elements such as mercury, lead and arsenic.

Clean coal technologies are a range of technological options that improve the environmental performance of coal. For example, converting coal to gas through integrated gasification combined cycle (IGCC) uses up to 40 per cent less water, and up to 90 per cent of mercury emissions can be captured, compared to conventional coal plants. Emissions of oxides of nitrogen (NOx) are reduced up to 99 per cent, and particulate emissions are reduced to almost zero (World Coal Institute).

This process is clean and enables high efficiency of electricity generation. The reason is that using IGCC, coal is not combusted directly, but reacts with oxygen and steam to produce a synthesis gas composed mainly of hydrogen and carbon monoxide. This synthesis gas is cleaned of impurities and then burnt in a gas turbine to generate electricity.

The world is also exploring hydrogen-based energy systems, in which hydrogen is used to produce electricity from gas turbines and fuel cells. Fuel cells use electrochemical reactions between hydrogen and oxygen instead of a combustion process to produce electricity. Hydrogen does not occur naturally in usable quantities, but we can use fossil fuels to manufacture it.

Coal, with the biggest and most widespread reserves of any fossil fuel, is a primary candidate to provide hydrogen, and through coal gasification, this process can generate the increasing global demand of electricity.

Europe, Japan, the USA and New Zealand all have active hydrogen programmes and are considering coal as an option to produce hydrogen.

Energy is vital to our national development. Let's consider coal with an open mind!